Velocity distributions in a hydrocyclone separator

 The internal three-dimensional flow field in a hydrocyclone was studied using laser velocimetry. Seven axial planes were investigated for three different inlet flow rates and three independent and different rejects rates. Results at each measurement plane showed that the measured tangential velocity profile behaves like a forced vortex at the region near the air core, and like a free vortex in the outer portion of the flow. The peak nondimensional tangential velocity decreases as the distance from the inlet region increases, however, the peak dimensional tangential velocity increases as the distance from the inlet region increases. The nondimensional peak tangential velocities are approximately equal for all of the flow rates. The magnitude of the tangential velocity increased in the inner forced vortex region as the rejects rate was increased. Backflows exist in the axial velocity profile near the inlet region, but these reversed flows disappear in the exit region. The dimensional vorticity is proportional to inlet flow rate and decreases with increasing rejects flow rates. Received: 27 February 2001/Accepted: 19 June 2001